On Sat, Jul 08, 2017 at 10:43:24AM +0200, Ingo Molnar wrote:
>
> * Paul E. McKenney <[email protected]> wrote:
>
> > On Fri, Jul 07, 2017 at 10:31:28AM +0200, Ingo Molnar wrote:
> >
> > [ . . . ]
> >
> > > In fact I'd argue that any future high performance spin_unlock_wait()
> > > user is
> > > probably better off open coding the unlock-wait poll loop (and possibly
> > > thinking
> > > hard about eliminating it altogether). If such patterns pop up in the
> > > kernel we
> > > can think about consolidating them into a single read-only primitive
> > > again.
> >
> > I would like any reintroduction to include a header comment saying exactly
> > what the consolidated primitive actually does and does not do. ;-)
> >
> > > I.e. I think the proposed changes are doing no harm, and the
> > > unavailability of a
> > > generic primitive does not hinder future optimizations either in any
> > > significant
> > > fashion.
> >
> > I will have a v3 with updated comments from Manfred. Thoughts on when/where
> > to push this?
>
> Once everyone agrees I can apply it to the locking tree. I think PeterZ's was
> the
> only objection?
Oleg wasn't all that happy, either, but he did supply the relevant patch.
> > The reason I ask is if this does not go in during this merge window, I need
> > to fix the header comment on spin_unlock_wait().
>
> Can try it next week after some testing - let's see how busy things get for
> Linus
> in the merge window?
Sounds good! Either way is fine with me.
Thanx, Paul
